Maths - Mensuration
- Option : A
- Explanation :
Given, BD = 40 cm, AM =16 cm , NC=12cm
∴ Here, BD divides quadrilateral in two triangles.
Now,
Area of ΔABD = 1/2 x BD xAM
1/2 x 40 x 16 =320 cm∧2.
∴ Area of ΔBCD = 1/2 x BD x NC
=1/2 x40 x12=240 cm∧2
Area of quadrilateral
ABCD = 320 + 240 = 560 cm∧2
2. A cuboid is of dimensions 5 cm × 2 cm × 5 cm. How many such cuboids may be joined to form a cube?
- Option : D
- Explanation : (D) Given that, sides of a cuboid are 5cm, 2cm and 5cm.
Volume of cuboid = 5 × 2 × 5 = 50cm3
Let the side of the cube formed with minimum number of cuboids = x
Hence, volume of the cube = x3
Let, number of cuboids required = n
Hence, n × 50 = x3
n × 50 must be perfect cube i.e.
minimum value of n = 2 × 2 × 5 = 20
Volume of the cube formed = 20 × 50 = 1000 cm3
So, required cuboids = 20
- Option : C
- Explanation : Given, lb = x.
bh=y,lb=z.
lb x bh x lh = xyz.
l2 b2 b2 =xyz
Volume = lbh = √xyz
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